Scientific Research
As a structural biologist, I use cryogenic electron microscopy (cryoEM) to visualize proteins with atomic-level detail.
Current Research - Immune Cell Signaling
As a postdoctoral researcher in the Campbell Laboratory at Fred Hutchinson Cancer Center, I investigate how immune cells sense and respond to their environment. My work focuses on leukocyte integrins — proteins on the surface of immune cells that control adhesion, migration, and activation. Using cryoEM, I study how these large, flexible membrane proteins switch between functional states and interact with cytosolic binding partners, with the goal of understanding the structural basis of immune signaling.
Doctoral Research - The Molecular Machinery of Cellular Acidification
My PhD research in the Rubinstein Laboratory at the Hospital for Sick Children (University of Toronto) focused on V-type ATPases — ancient molecular machines that use ATP to pump protons across membranes, acidifying compartments essential to cellular digestion, signaling, and cellular housekeeping. I determined the first structures of the Golgi-specific V-ATPase isoform, revealing how subtle structural differences between isoforms contribute to their distinct biological roles. I also captured transient assembly intermediates that shed light on how these machines regulate their activity.
Methods
My research relies on the full cryoEM pipeline: protein expression and purification, grid preparation, data collection and processing, and structural analysis. I have extensive experience working with challenging samples, including small flexible membrane proteins and fragile, aggregation-prone complexes.
Publications
Vasanthakumar T, Keon KA, Bueler SA, Jaskolka MC, and Rubinstein JL (2022). Coordinated conformational changes in the V1 complex during V-ATPase reversible dissociation. Nature Structural & Molecular Biology, 29, 430–439.
Vasanthakumar T and Rubinstein JL (2020). Structure and roles of V-type ATPases. Trends in Biochemical Sciences, 45, 295–307.
Vasanthakumar T, Bueler SA, Wu D, Beilsten-Edmands V, Robinson CV, and Rubinstein JL (2019). Structural comparison of the vacuolar and Golgi V-ATPases from S. cerevisiae. PNAS, 116, 7272–7277.